The Manhattan School for Children (MSC) on West 93rd Street in New York City was the city’s first to cultivate a rooftop hydroponic laboratory greenhouse in 2010.

In the soil-less, 1 400 square foot greenhouse, which captures and recirculates rainwater to the roots of plants, 8 000 pounds of vegetables can be produced every year.

The greenhouse was the brainchild of two parents who had paid a visit to the Science Barge, a floating urban farm docked in Yonkers in the Big Apple. The mums asked New York Sun Works, the non-profit green-design group that built the barge, to create the bright, open and wheelchair-accessible space, covered by glass and entered from the school’s third floor.

It includes a rainwater catchment system, a weather station, a sustainable air conditioner made of cardboard, a worm composting centre and solar panels. In the centre of the room is a system resembling a plant-filled hot tub – an aquaponics system home to a community of tilapia, whose waste is converted into nitrate. The system loses water only when it evaporates to help cool plants, consuming only a tiny fraction of the water that a field of conventional dirt does.

The food produced in the greenhouse is distributed by a farm stand in the school’s lobby, a nearby shelter and the school cafeteria. Says the principal: “It’s also important to remember that the greenhouse is a living science laboratory.”

The greenhouse is being replicated in other schools in the Big Apple. In Public School (PS) 333, lettuces line the walls and ladybirds congregate on the whiteboard in the rooftop ‘classroom’. Rainwater and aquaponic tanks and special blocks of nutrients help the plants thrive.

PS 686 – The Brooklyn School of Inquiry – is also in line for a rooftop greenhouse. Founded in 2009, with a special focus on ‘gifted and talented’ students, the school’s proposed ‘green’ classroom will be a 2 500 square foot facility boasting the same resources as the MSC, and able to accommodate two classes concurrently.